Bone markers blood and urine tests and osteoporosisThroughout life - PDF document

Bone markers (blood and urine tests) and osteoporosisThroughout life, your skeleton is continually renewing itself. Cells called osteoclasts break down old bone (bone resorption) and cells called osteoblasts lay down new bone (bone formation). This process of renewal is often described as bone turnover and it enables bones to repair microscopic damage and maintain their strength. As we become older, the rate of bone turnover increases. As a consequence of this increase, the amount of bone that is removed often exceeds the amount that is formed. This imbalance leads to bone loss as part of the normal aging process, and may lead to osteoporosis making an individual more at risk of fracture.What are bone markers?During the bone remodelling process, chemicals are produced which can be detected in the blood and urine. These products are known as ‘biochemical markers of bone turnover’ or bone markers. An assessment of levels of these markers can be used to measure the rate of bone turnover, thus providing useful information about factors that might aect bone strength. Bone markers are classied as markers of either bone resorption or bone formation. These processes are closely linked together so either typeof marker will reect the rate of bone turnover.Where can I get this test?The test is only currently available in specialist centres when it is felt that the additional information provided could aect the type of drug treatment oered - your GP will be able to advise whether a consultant referral is required. Bone markers are also used in research to assess eects of treatments in drug trials or as part of an assessment of fracture risk. Bone marker tests are not generally requested by GPs. There are many factors, such as time of the day and other medical conditions you might have, that can aect the interpretation of bone marker testing and most GPs won’t have the experience or the equipment to use these tests eectively. It is not advisable to buy a self-testing kit over the counter or on the internet because the accuracy or usefulness of these kits is unproven.How are bone turnover markers measured?Bone resorption markers can be measured in blood or urine. Bone formation markers are measured in blood. The two markers generally used are called PINP and CTX and these are the ones recommended in international expert guidance. These are both blood tests.Some hospitals still use NTX which is a urine marker. Bone alkaline phosphatase (a blood test) is the other marker that is also sometimes used to help understand whether you are aected by other bone conditions but not to check if a drug is working.Bone markers are summarised in the table below: Bone markersof formationBone markersof resorption) cross-linkingcollagen (blood test)Procollagen type I Npropeptide () cross linkingcollagen (urine test) What is osteoporosis?Osteoporosis occurs when the struts that form the mesh-like structure inside bones become thin. This causes the bone to become fragile and break easily, even after a minor bump or fall. You might hear these breaks described as ‘fragility fractures’. The terms ‘fracture’ and ‘broken bone’ mean the same thing.Fractures can occur in many parts of the body, but they are most common in the wrists, hips and spine. It’s these broken bones that can cause pain, rather than osteoporosis itself. Spinal fractures can also cause height loss and a curved spine. A blood or urine sample is taken to assess bone marker levels and sent to the laboratory for testing. Because bone turnover is highest in the morning and decreases signicantly by lunchtime, blood samples for some markers such as CTX need to be taken early in the morning after fasting, with follow-up samples taken at a later date, at the same time of the day. PINP, however, can be measured at any time of day. If you are having a urine test, you will be asked to provide a sample as the second specimen of the morning (you pass urine once and then collect a specimen the second time) and as early as possible.How are bone marker tests used?Th

ese tests may be used for one of three reasons: To measure bone turnover as part of an assessment of bone strength and fracture risk. There haven’t been many research trials to prove how eective this is, so other methods are usually used to assess bone strength, including a bone density scan to measure your bone density, along with your other risk factors. To monitor the eectiveness of osteoporosis drug treatments. Most treatments work by slowing the rate of bone resorption. The rate of bone formation also slows, but the overall eect is that the two processes come back into balance, leading to improved bone strength. The eect of a drug treatment on bone turnover can be assessed using bone markers within six months of starting treatment. In research trials, to assess osteoporosis drugs in development. Although there is evidence to suggest the value of bone marker tests as outlined above, expert opinion is divided on how useful or necessary they are and further research is required to establish how they should be best used in the management of osteoporosis. A UK independent review in 2014, which looked at whether bone markers should be used to see if a drug treatment is working, concluded there was insucient evidence available to make recommendations. International expert guidance, however, says that although more research is needed, bone markers can be useful in some situations.How do I know my osteoporosis treatment is working if I’m not oered a bone marker test?You can be condent that all of the licensed drug treatments for osteoporosis have been clinically tested and research has proven they reduce the risk of breaking bones. Having a bone density scan provides some information and may be useful, although it doesn’t tell you everything about your bone strength or show conclusively whether a drug is working or not.If you have a fracture while on treatment, this doesn’t always mean the drug is not working – no drug is 100% eective. But if you continue to break bones, talk to your doctor. Depending on your circumstances, they may suggest a dierent drug or refer you to a specialist for further advice and care.Getting more information and supportWe hope this fact sheet will help you feel more informed and more condent when discussing your bone health with your medical team.For more information about osteoporosis and bone health, including fact sheets on all available drug treatments, visit our website at theros.org.uk/info or order more of our printed publications.If you need more information or support, talk to your healthcare professional.You can also call our specialist Helpline nurses with any questions or concerns about bone health, for free, on 0808 800 035, or email them at nurses@theros.org.uk Content reviewed: December 2018 (updated December 2021)This information is based on the latest evidence andclinical practice. It should not replace advice from your own healthcare professionals.To give us feedback on this fact sheet, email us at health.info@theros.org.ukWe provide our information free of charge. To make a donation or become a member, visit theros.org.uk or call 01761 473 287 To view or order more information about osteoporosis and bone health:theros.org.uk/info 01761 471 771 info@theros.org.ukTo contact our specialist nurses:0808 800 0035 nurses@theros.org.uk @RoyalOsteoSoc BMO/DEC21 President: HRH The Duchess of Cornwall. Formerly known as the National Osteoporosis Society. President: HRH The Duchess of Cornwall. Formerly known as the National Osteoporosis Society. Royal Osteoporosis Society is a registered charity no. 1102712 in England and Wales, no. SC039755 in Scotland, and no. 1284 in Isle of Man. Royal Osteoporosis Society is a registered charity no. 1102712 in England and Wales, no. SC039755 in Scotland, and no. 1284 in Isle of Man. Registered as a company limited by guarantee in England and Wales no. 4995013, and foreign company no. 006188F in Isle of Man. Registered as a company limited by guarantee in England and Wales no. 4995013, and foreign company no. 006188F in Isle of Man.